Dresden 2009 – wissenschaftliches Programm
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MA: Fachverband Magnetismus
MA 40: Poster II: Bio- and Molecular Magnetism (1-9); Magnetic Coupling Phenomena/Exchange Bias (10-15); Magnetic Particlicles and Clusters (16-29); Micro and Nanostructured Magnetic Materials (30-51); Multiferroics (52-64); Spin Injection in Heterostructures (65-67); Spin-Dyn./Spin-Torque (68-93); Spindependent Transport (94-108)
MA 40.19: Poster
Freitag, 27. März 2009, 11:00–14:00, P1A
The use of XMCD to determine the magnetic and structural composition of nanoparticles — •Daniela Nolle1, Eberhard Goering1, Liberato Manna2, Albert Figuerola2, Thomas Tietze1, Sebastian Brück1, and Gisela Schütz1 — 1Max Planck Institute for Metal Research, Heisenbergstr. 3, 70569 Stuttgart, Germany — 2National Nanotechnology Laboratory of CNR-INFM, Unità di Ricerca IIT, Distretto Tecnologico ISUFI, via per Arnesano km. 5, I-73100 Lecce, Italy
We have investigated different FePt/FeOx nanoparticles using X-ray magnetic circular dichroism (XMCD). All investigated nanoparticles are produced in a "one-pot"-synthesis and consist of a FePt core (fcc structure) and a FeOx shell (inverse spinell structure) in different volume ratios.To determine the structural and magnetic composition of the nanoparticles we performed XMCD measurements both in the surface sensitive total electron yield mode (TEY) and the bulk-sensitive transmission mode. The measured spectra have been analysed in terms of a linear superposition of suitable reference data of metallic FePt, Magnetite (Fe3O4), and Maghemite (γ-Fe2O3). A comparison between TEY and transmission measurements for the 18 nm hybrid system shows, that the iron oxide shell is mainly magnetite like, while the surface has predominantly maghemite character.This method demonstrates the strength of simultaneously performed XMCD experiments utilizing different scanning depth measurement modes and provides a detailed structural and magnetic model for the investigated nanoparticles, which is consistent to corresponding SQUID measurements.